Process of refining fat-soluble vitamin-containing materials



Patented Dec. 16, 1941 raocass F narmmo FA'r-soLuBLE VITAMIN-CONTAININGMATERIALS Loran 0. Buxton, Belleville, N. J., and Eric J. Simons, NewYork, N. Y., assignors to National Oil Products Company, Harrison, N.J., a corporation of New Jersey No Drawing. Application January 11,1941,

Serial No. 374,080

15 Claims.

This invention relates to a process for refining fat-solublevitamin-containing materials, more particularly to the refining of fishliver oils and concentrates prepared therefrom by adsorption ofundesirable constituents from said materials.

As is well known in the art, fat-soluble vitamincontaining oils andconcentrates prepared therefrom have been used for a wide variety ofuseful purposes, particularly in the nutritional fields. However, manyof these fat-soluble vitamin-containing materials, particularly productsof a fish origin, have characteristic tastes and odors of an unpleasantnature; furthermore, the color of these materials is often dark, thusrendering the materials unattractive from a consumer standpoint. Theseundesirable properties have in some cases tended to limit the field ofusefulness of these materials; as a result, there has been a greatdemand for a simple and effective process for removing the objectionablecolor, taste and odor therefrom.

To meet this demand a process for adsorbing the objectionable odor,taste and color from fatsoluble vitamin-containing materials has beendeveloped. The process is disclosed and claimed in copending applicationSerial No. 227,599, filed August 30, 1938, in the name of Buxton, andmvolves contacting a solution of a fat-soluble vitamin-containingmaterial with activated carbon under anaerobic conditions. Because ofthe excellent solubility of fat-soluble vitamin-containing materials inhydrocarbon and halogenated hydrocarbon solvents of a relativelynon-polar nature, these substances are recommended for use as solventsfor the fat-soluble vitamin-containing materials in this process. Oursubsequent investigations have revealed, however, that when solutions offat-soluble vitamin-containing materials in such solvents are contactedwith certain of the adsorbents, particularly highly active ones such asactivated earths and clays or blood charcoal, appreciable amounts of thevaluable vitamins may be adsorbed along with the undesirableconstituents and thereby lost.

It is an objectof this invention to provide an' improved process forremoving color, taste and odor from the fat-soluble vitamin-containingmaterials.

It is a more specific object of this invention to provide a process foradsorbing color, taste and odor from fat-soluble vitamin-containingmaterials, which process may be advantageously employed with highlyactive adsorbents.

We have made the surprising discovery that the undesirable constituentscontained in fatsoluble vitamin-containing materials which a.

responsible for objectionable odor, color and taste may be removedtherefrom without the loss of any of the valuable vitamins by dissolvingthe fat-soluble vitamin-containing material in a hydrocarbon orhalogenated hydrocarbon solvent of a relatively non-polar nature andcontacting the solution thus prepared with an adsorbent, provided thesolvent employed containsarelatively small amount of anoxygen-containing organic compound having a polar functional grouping.The term polar functional grouping is employed herein to denote thefunctional grouping in a compound which tends to produce an unbalancedelectronic structure and thereby activates the molecule and imparts acharacteristic dipole moment thereto; examples of such polar functionalgroupings are the hydroxyl group, the carbonyl group, the carboxylgroup, and the ester grouping. We have found that the incorporation of acompound of the above type in the hydrocarbon or halogenated hydrocarbonsolvent employed effectively prevents any substantial adsorption of thefat-soluble vitamins even though the most highly active adsorbents areemployed; furthermore, these compounds do not in any way inhibit orrepress adsorption of the constituents responsible for the color, odorand taste of the fat-soluble vitamin-containing material. The preferredembodiment of our invention involves contacting a solution of a fishliver oil or concentrate prepared therefrom in a mixture containing ahydrocarbon or a holagenated hydrocarbon solvent of a relativelynon-polar nature and less than 10% of a lower aliphatic alcohol underanaerobic conditions with a highly active adsorbent, such as bloodcharcoal or an activated earth or clay; by operating in this mannerhighly valuable products may be inexpensively produced from the readilyavailable fish liver oils. The products produced by the process of ourinvention are almost completely devoid of objectionable color, taste andodor, but have practically the same vitamin content as the originalmaterial;

" hence these products will obviously be adaptable desirable color,taste or odor; thus, for example,

fish liver oils, such as cod liver oil, shark liver oil, ling cod liveroil, halibut liver oil, sword fish liver oil, etc., may be treated.Furthermore, concentrates prepared from these oils by saponification ofthe oil and extraction of the unsaponifi able fraction may also beadvantageously processed by this invention; highly potent productsprepared by subjecting fish liver oils to high vacuum distillation mayalso be treated with success. Other materials having obiectionablecolor, odor and taste and containing vitamin A or D in either thealcohol or ester form, as well as materials containing the otherfat-soluble vitamins, 1. e. vitamins E and K, may also be advantageouslytreated; thus, for example, wheat germ oil may be refined by the processof this invention.

The adsorbents employed may be practicallyused. Any one of the manyaluminum oxide adsorbents known to the art may also be employed.

Preferably the more highly active adsorbents such as blood charcoal oracid treated earths or clays,

or mixtures of such adsorbents, are used, since the removal of theobjectionable color, odor and taste is thereby rendered more eflicient.

The fat-soluble vitamin-containing material may, in accordance with thisinvention, be contacted with the adsorbents in a variety of manners.Preferably the process is carried out under anaerobic conditionsaccording to the procedure described in copending application Serial No.227,599 of Buxton, filed August 30, 1938. In accordance with thisprocedure one of the adsorbents above mentioned'is first thoroughlydeaerated by agitating the adsorbent with .the mixture to be used as thesolvent for the fat-soluble vitamin-containing material. The solventmixture employed should preferably consist of between about 90% andabout 99% of a hydrocarbon or halogenated hydrocarbon solvent of arelatively non-polar nature, and between about 1% and about 10% of anoxygen-containing organic compound having a polar functional grouping.The hydrocarbon or halogenated hydrocarbon solvent used may be hexane,heptane, octane, ethylene dichloride, carbon tetrachloride, cyclohexane,methyl cyclohexane, benzene, similar solvents of a relatively non-polarnature, or mixtures thereof. Among the oxygen-containing solvents whichmay be employed are methyl alcohol, ethyl alcohol, propyl alcohol,isopropyl alcohol, benzyl alcohol, cyclohexanol, phenol, acetone,methylethyl ketone, acetaldehyde, propionaldehyde, methyl acetate,methyl formate, ethyl acetate, acetic acid and mixtures of suchcompounds; we prefer to employ the lower aliphatic alcohols such asmethyl alcohol, ethyl alcohol or isopropyl alcohol, since thesecompounds are cheap, readily available and extremely effective. Thedeaeration is preferably accomplished by mixing the solvent mixture withthe adsorbent in amounts such that the weight of the solvent mixture isat least four times, and preferably between about twenty and about fortytimes, the weight of the adsorbent, the particular amount of adsorbentvarying with the amount of fatsoluble vitamin-containing material to berefined, and then agitating the mixture thoroughly until the air isexpelled from the adsorbent and,

a solvent atmosphere created directly over the adsorbent to preventaccess of air. Heat and reduced pressures may'be applied to assist thedeaeration, if desired. It is-to be understood, however, that thedeaeration may be carried out equally satisfactorily by agitating theadsorbent with the hydrocarbon or halogenated hydrocarbon solvent, andthen adding the desired amount of the oxygen-containing solvent to thedeaerated mass. Furthermore, it is not necessary to add all the solventto the adsorbent prior to deaeration, since a portion can be used todeaerate the adsorbent and the remainder subsequently added to the masseither alone or along with the material to be refined. In any event atthe termination of the deaeration treatment, entrapped air will beentirely expelled from the adsorbent and the vapors of the solvent willprevent air from contacting the adsorbent during the refining operation.

When the adsorbent has been deaerated, thefat-soluble.vitamin-containing material to be refined may then be addedto the deaerated mixture; the amount of material added should be suchthat the weight of fat-soluble vitamincontaining material is not greaterthan the weight of the solvent mixture, and preferably is between about15% and about 20% of the weight'of the solvent. The fat-solublevitamin-containing material added may be dissolved in a solventcompatible with the solvent mixture in which the adsorbent is suspended;thus, for example, solutions containing fat-soluble vitamins such asthose obtained by the solvent extraction of fish livers or fish liveroils may be treated. The mass may then be stirred for a suitable time,with the application of heat and vacuum, if desired, until adsorption ofthe undesirable constituents has been completed; it will be found thatapproximately one hour is usually sufiicient to adsorb the bulk of theobjectionable constituents from the fat-soluble vitamin-containingmaterial. The suspended adsorbent may then be permitted to settle, themass filtered and the residue washed with the particular solvent mixtureemployed in order to remove any fat-soluble vitamins from theadsorbents. The wash liquids may then be combined with the filtrate, thesolvent evaporated andthe refined fat-soluble vitamin-containingmaterial thus recovered.

It is to be understood that the process of our invention may be modifiedsomewhat. Thus, for example, the fat-soluble vitamin-containing materialmay be dissolved in a suitable solvent mix ture of the type abovedescribed and this solution then percolated through a bed of anadsorbent, preferably one which has been deaerated by contact with asolvent of a type similar to that used for the material being refined;this method of operation has the advantage of being substantiallycontinuous. If the fat-soluble vitamin-containing material to be refinedcontains free fatty acids, 9. portion of these may be removed prior torefining in accordance with the process described in our copendingapplication Serial No. 227,600, filed August 30, 1938. The adsorbentsused may contain filter aids to assist in their removal from the refinedmaterial. Other modifications may also be introduced without departingfrom the scope of this invention.

The following examples are illustrative of our invention; amounts aregiven in parts by weight.

Example I 2.5 parts of an adsorbent containing 1 part of and 10 parts ofmethanol.

an activated earth sold under the tradename of Tonsil" and 1.5 parts ofan activated carbon were deaerated by agitation with a mixture of 95parts of ethylene dichloride and parts of methyl alcohol. 25 parts ofsword fish liver oil containing 171,000 A units per gram were added tothe deaerated mass and the whole mixture stirred for about one hour. Atthe end of this time, the adsorbent was permitted to settle and was thenfiltered from the solution, washed with the solvent mixture employed,and the wash liquids combined with the filtrate; the solvent was thenevaporated from the combined solutions, whereby a product having noobjectionable color, taste or odor and containing 171,000 A units pergram was recovered. The same experiment carried out in the same mannerexcept that no methyl alcohol was added to the solution yielded aproduct containing only 120,000A units per gram.

Example II 5 partsof an activated earth sold under the tradename ofTonsil" were deaerated by agitation with a mixture of 190 parts ofcyclohexane and parts of acetone. 50 parts of crude shark liver oilcontaining 105,000 A units per gram and having an objectionable color,taste and odor were then added to the mixture and the whole mass stirredfor 30 minutes. The refined oil was then recovered as described inExample I. The resulting product contained 106,000 A units per gram andhad a pleasant color, taste and odor. The same experiment conducted inthe absence of the acetone yielded a product containing only 100,000 Aunits per gram.

Example III 10 parts of a decolorizing carbon sold under the tradenameof Darco 8-51 were deaerated by agitation with a mixture of 190 parts ofheptane 50 parts of crude shark liver oil containing 67,000 A units pergram and having an objectionable color. taste and odor were then addedto the mixture and the whole mass stirred for 30 minutes. The refinedoil was then recovered as described in Example I. The resulting productcontained 67,400 A units per gram and had a pleasant color, odor andtaste. The same experiment carried out in the absence of methanolyielded a product having a vitamin potency of only 60,600 A units pergram.

From the above description it will be evident that the process of ourinvention permits the more successful refining of fat-solublevitamincontaining materials by the adsorption method.

By reason thereof, this process will be of great value to the industry.

Since certain changes may be made in carrying out the above processwithout departing from the scope of the invention, it is intended thatall matter contained in the above description shall be interpreted asillustrative and not in a limiting sense.

Having described our invention, what we claim as new and desire tosecure by Letters Patent, is:

1. In a process for refining a fat-soluble vitamin-containing materialby contacting a solution of said material in a solvent selected from thegroup consisting of hydrocarbon and halogenated hydrocarbon solvents ofa relatively non-polar nature with an adsorbent, the improvement whichcomprises incorporating in the solution a relatively small amount of anoxygen-containing organic compound having a polar functional grouping.

2. In a process for refining a fat-soluble vitamin-containing materialby contacting a solution of said material in a solvent selected from thegroup consisting of hydrocarbon and halogenated hydrocarbon solvents ofa relatively nonpolar nature with an adsorbent, the improvement whichcomprises incorporating in the solution an amount of anoxygen-containing organic compound having a polar functional groupingequivalent to less than about 10% of the relatively non-polar solventemployed.

3. In a process for refining a fat-soluble vitamin-containing materialby contacting a solution of said material in a solvent selected from thegroup consisting of hydrocarbon and halogenated hydrocarbon solvents ofa relatively non-polar nature with an adsorbent, the im-' provementwhich comprises incorporating in the solution a relatively small amountof a lower aliphatic alcohol.

4. In a process for refining a fat-soluble vitamin-containing materialby contacting a solution of said material in a solvent selected from thegroup consisting of hydrocarbon and halogenated hydrocarbon solvents ofa relatively nonpolar nature with an adsorbent under anaerobicconditions, the improvement which comprises incorporating in thesolution a relatively small amount of an oxygen-containing organiccompound having a polar functional grouping.

5. In a process for refining a crude fish liver oil by contacting asolution of said oil in a solvent selected from the group consisting ofhydrocarbon and halogenated hydrocarbon solvents of a relativelynon-polar nature with an adsorbent under anaerobic conditions, theimprovement which comprises incorporating in the solution a relativelysmall amount of an oxygen-containing organic compound having a polarfunctional grouping.

6. A process for refining a fat-soluble vitamin-containing material,which comprises forming a deaerated mixture of an adsorbent and asolvent containing a substance selected from the group consisting ofhydrocarbon and halogenated hydrocarbon solvents of a relativelynon-polar nature and an oxygen-containing organic compound having apolar functional grouping, adding the fat-soluble vitamin-containingmaterial to said mixture, agitating the mass, removing the adsorbent,and recovering the refined material.

7. A process for refining a crude fish liver oil, which comprisesforming a deaerated mixture of an adsorbent and a solvent containing asubstance selected from the group consisting of hydrocarbon andhalogenated hydrocarbon solvents of a relatively non-polar nature andless than about 10% of an oxygen-containing organic compound having apolar functional grouping, adding the fish liver oil to the deaeratedmixture, agitating the mass, removing the adsorbent, and recovering therefined fish liver oil.

8. A process for refining a crude fish liver oil, which comprisesforming a deaerated mixture of an adsorbent and a solvent containing asubstance selected from the group consisting of hydrocarbon andhalogenated hydrocarbon solvents of a relatively non-polar nature andless than about 10% of a lower aliphatic alcohol, adding the fish liveroil to the deaerated mixture, agitating the mass, removing theadsorbent, and recovering the refined fish liver oil.

9. A process for refining a crude fish liver oil, which comprisesdeaerating an adsorbent by agitation with a solvent mixture containing asubstance selected from the group consisting of hydrocarbon andhalogenated hydrocarbon solvents of a relatively non-polar nature and anoxygencontaining organic compound having a polar functional grouping,adding the fish liver oil to the deaerated mixture, agitating the mass,removing the adsorbent, and recovering the refined fish liveroil.

10. A process for refining a crude fish liver oil, which comprisesdeaerating an adsorbent by agitation with a solvent mixture containing asubstance selected from the group consisting of hydrocarbon andhalogenated hydrocarbon solvents of a relatively non-polar nature andless than about methyl alcohol, adding the fish liver oil to thedeaerated mixture, agitating the mass, removing the adsorbent, andrecovering the refined fish liver oil.

11. A process for refining a crude fish liver oil, which comprisesdeaerating an adsorbent by agitation with a solvent mixture containing asubstance selected from the group consisting of hydrocarbon andhalogenated hydrocarbon solvents ot a relatively non-polar nature andless than about 10% isopropyl alcohol, adding the fish liver oil to thedeaerated mixture, agitating the mass, removing the. adsorbent, andrecovering the refined fish liver oil.

12. A process for refining a crude fish liver oil, which comprisesdeaerating an adsorbent by agitation with a solvent mixture containing asubstance selected from the group consisting of hydrocarbon andhalogenated hydrocarbon solvents of a relatively non-polar nature andless than obout 10% acetone, adding the fish liver Oil to the deaeratedmixture, agitating the mass, removing the adsorbent, and recovering therefined fish liver oil.

13. A process for refining fish liver oils, which comprises deaeratingan adsorbent containing an activated carbon and an activated earth byagitation with a solvent mixture containing ethylene dichloride and lessthan about 10% methyl alcohol, adding the fish liver oil to thedeaerated mixture, agitating the mass, removing the adsorbent, andrecovering the refined fish liver oil.

14. A process for refining fish liver oils, which comprises deaeratingan adsorbent containing an activated carbon and an activated earth byagitation with a solvent mixture containing heptane and less than about10% isopropyl alcohol, adding the fish liver oil to the deaeratedmixture, agitatting the mass, removing the adsorbent, and recovering therefined fish liver oil.

15. A process for refining fish liver oils, which comprises deaeratingan adsorbent containing an activated carbon and an activated earth byagitation with l a solvent mixture containing cyclohexane and less thanabout 10% acetone, adding the fish liver oil to the deaerated mixture,agitating the mass, removing the adsorbclot, and recovering the refinedfish liver oil.

\ LORAN O. BUXTON.

ERIC J. SIMONS.

